A UK-based group of creative crafters called Nottingham Hackspace has revamped its snack dispensary into a tweeting machine that keeps its members accountable for what they eat. After a successful pledge drive, the group was able to buy the vending machine off eBay. The hackers then enhanced the purchase with Arduino, an open source electronics prototyping platform.

Using Arduino, they've modified the cash payment system with a little reader onto which members tap their cards. The cards have a little RFID (radio-frequency identification) chip that wirelessly transmits who they are and how much money is on their card to the vending machine.

It also communicates with the Nottingham Hackspace server, Holly, who then tweets your candy bar purchase. We're thinking that we'll need to get one of those in our office.